Thursday, July 9, 2015

Factoid of the day: A stellar journey?

The factoid of the day is the excitement that New Horizons Pluto explorer is about to take a few snaps of the dwarf planet, assuming it points the camera the right way, and doesn't just take selfies.  That should happen but does require some very delicate, very long-distance telecommunication from here on earth to the flying obersvatory.

One highly touted amazing! fact the media have given us to help make the event more festive is that the explorer is by far the fastest object we have ever sent into space, according to recent news releases that have appeared as the mission nears the 'dwarf planet'.  Its speed is about 9,000 mph. It had to be micro-miniaturized so all of its stuff could fit in a small, light-weight package (essentially, one might say, carry-ons only).  That was apparently quite a skillful engineering feat.

New Horizons' exciting (fake) adventure picture
This picture is from the NASA website, and while they do tell you in the small print that this is an artist's conception, not the real thing, this and other images are part of the promotional effort to sell space adventures.  For many space discoveries they, or the news media or journals touting them, only have artist's conceptions.  So they are free to take the proverbial artistic license to make them as exciting as they can. Such excited hype is only natural, we guess.  But in this case, if all goes well, there really will be images, in the near future.  For someone interested in actual science, they will be far more interesting and, yes, truly exciting than the made-up versions.  Hopefully we will learn at least a few things about this very distant snowball.

In fact, and without any element of hyperbole, the great distance from here to Pluto is quite thought-provoking.  New Horizons is zooming so fast as to make your head spin.  In round numbers (and why not?), it covers about 80,000,000 miles per year (not counting leap day!).  That's about 10^8 miles. To put that in perspective we shouldn't compare it, say, to a cop-free transit of I-80 from New York to where we live in central Pennsylvania, though, given the nature of the I-80 traffic, that might take a few light years.  Maybe some more space-related comparison would be better.

So, to start with, the nearest star to the earth is Proxima Centauri, which is about 4.24 light years away.  A light year is about 5.9 x 10^12 miles, a mere 10,000 times faster than New Horizons, give or take an order of magnitude.  That means that Proxima is about 2.4 x 10^13 miles from here (forgetting what season and hence what relative position, the Earth is in at launch-time).

If we have our math close to right, that means, again on the back of an envelope, that a mission to zip to the nearest star or any planet it may have--the kind of voyage that space agencies cleverly hint at without actually promising, would take a mere 100,000 to 1,000,000 years, give or take a few millennia.

Any such exploration is unlikely to involve astronauts! The invention of agriculture occurred roughly 10,000 years ago.  100,000 years ago all human ancestors were scrounging around Africa for wildebeests, roots, and berries or perhaps had started to expand into Eurasia (where they had different kinds of deer, roots, and berries).  A million years ago all our ancestors were grunting around in Africa, with some side-branches perhaps in Eurasia.

If a very smart Homo erectus (probably some nerdy teenager) had sent a "Hiya!" radio message into deep space, it would just have got there this week, or maybe next.  It will take a while before we hear back, if the ETs got it, understood the early erectine language, had radios, and decide that it wasn't spam and that they should answer.

So, let's plan a voyage to find ETs on another planet!  Right off the bat, the space agencies can post 'artist's interpretation' of what's out there, and after all, if it fails, there won't be any humans on earth to know that the money was wasted.  Or better yet, here's a far better and more sane idea when it comes to exploring space and searching for ETs:  let's have the video game industry (A) try it themselves, or (B) simulate it.  They have the funds, and the government has more important things on its plate, like health care and poverty and so on.  Of the two approaches, Plan B would make some actual sense, even if NASA, ESA, or SpaceX weren't involved (even assuming their rockets didn't blow up).


David Evans said...

New Horizons may be the fastest object we have ever sent out of the Solar System, but it's very far from being the fastest we could send. Forty years ago Project Daedalus produced a detailed design for a flyby mission to Barnard's Star with a 50 year flight time. I'm sure we could do better now if we put our mind to it.

Ken Weiss said...

Thanks for pointing this out, which we hadn't known of. We were just trying to have a bit of fun given all the news stories about the Pluto explorer. A camera fly-by even at 50 years would be rather a remote thing to do, though of course interesting. Whether that is actually possible or practicable (for example, it would have to have no Earth-based communication being around 6 light years away, and so on. Even at 50 years pictures would take 6 years to come back, so we're talking about something rather remote in regard to human experience.

The real story to me, personally, is the ever-present subtle hinting that if we just keep investing in space exploration, we're going to send people out to find aliens on these stars' planets. It becomes, also, a matter of relative investment and importance, and hence about the politics of science investment. Even within the space budget, I think we learn far more from unmanned than manned efforts. But that is just a personal opinion, and I'll be as interested to see the Pluto pictures as anyone, but being a spoil-sport, not particularly sanguine about all the hype that's likely to accompany them.

If I were an aerospace engineer instead of a geneticist I would be thoroughly excited by the possibility, of course, and would work on it!

Anonymous said...

Hidden message? They even put a date/time on it.


Ken Weiss said...

Aw, Manoj, you kill-joy! If NIH can promise precision genomic medicine why can't NASA engage in just as much fantasy? Of course, like the High Priests of Promise (HPPs, here, of NIH), 'precision' is so vague a term that the guarantee is sure to be fulfilled (or, that is, success can be claimed). In a sense, 'life' is just as vague. Any ongoing chemical reaction can be claimed a triumph if found. Since planets are generally molecularly dynamic, and since we already know that 'organic' molecules exist all over the place, this too is a sure-bet.

Of course, the HPPs know very well that they are suggesting, without actually saying (since it isn't true as they know) that people are inferring 'precision' as meaning almost anything is genetic and will be treated or cured or prevented; and likewise, people are going to be inferring life as critters, cute or even ominous, maybe even ones that look like Hollywood ETs.

Still, buried in all of this is the genuinely interesting, and occasionally even important, science itself.

David J. Littleboy said...

"Since planets are generally molecularly dynamic, and since we already know that 'organic' molecules exist all over the place, this too is a sure-bet."

Exactly. Especially since the definition of "organic" is not "functional" (which is the translation into Japanese), but "consists mostly of carbon and hydrogen." You basically can't not find organic molecules if you look.

By the way: 9,000 mph may sound zippy fast and impressive, but everything in low earth orbit (Hubble, ISS, and tons of space junk) is moving faster than that. LEO is insane (one orbit takes 90 minutes or so), it's seriously amazing that the Hubble works at all. LEO is just barely above the earth's surface (if you draw things to scale so whole the earth fits on a page), and we're stuck there because we spent so much money on the shuttle and ISS that we didn't have money left over to put stuff higher up. And we spent that money to have manned missions, which add nothing to the science, but increase the costs astronomically.

By the way, there's a problem with the SETI game that's Hedi Lamarr's fault. She invented spread-spectrum communication (the frequency hopping bit), which has the feature (it was invented for use in secure communication) that you can't even differentiate between background noise and there being a signal there if you don't know in advance the pattern used for the frequency hopping. Basically, if your civilization has been thinking at all, it'll be doing something that's arbitrary, random, and really really hard. (E.g. digital TV, which only occasionally broadcasts an actual image, and spends most of its time broadcasting descriptions of how to compute the image from a previous image (i.e. changes to an image).

Ken Weiss said...

Very interesting! Hedy Lamarr?? I had no idea of that aspect of her life. We can also thank the likes of Carl Sagan (many still rue his departure) for giving ideas of life-out-there some rather silly imagery that was good for television audiences but not for serious science (the plate with inscriptions and the tape or disc with a Beetles song--whatever all that was, I conveniently can't remember). Billions and Billions.....

David Evans said...

The Hedy Lamarr problem is why just eavesdropping on routine communications probably won't work. There are several other things worth listening/looking for:

Radar pulses, which an advanced civilization might be using to track asteroids.
Messages intentionally directed at us.
Exhaust signatures from starships, or laser beams being used to accelerate space probes.
A star with an anomalous spectrum due to a civilization using some or all of its light output.

and others.
Centauri Dreams is a good source for some of this (though obsessed with Pluto at the moment)

Ken Weiss said...

All very interesting! What the public doesn't know perhaps can hurt them (in the pocket book, if nowhere else)? It all seems (to me) to reinforce the idea that this sort of exploration should be commercialized (after all, handing things off to the private sector is our national mantra these days) where their job is letting the imagination run wild!